Using glass makes is easier to start your next print, because you can use clips to hold the glass to the heated bed. By just switching the glass plates you are ready for you next print. You can usea piece of kapton to stick a thermistor on top of the glass, for making accurate readings of the bed temperature.
ReprapWorld is the number one webshop for all your reprap supplies for your 3D printer. We have a large collection of 3D printer components, from our famous electronics lines to filament from our own production. And everything is at a very competitive price!